It hasn’t been a good week for those of us hoping hostilities in the Leave side of the EU referendum would simmer down – Arron Banks, the UKIP financier and founder of the Leave.EU campaign, gave an interview attacking his Vote Leave rivals as “establishment” yesterday, while The Times reported an “attempted coup” by Bernard Jenkin to unseat Dominic Cummings as Vote Leave’s campaign director. The fight thickened today as The Independent quoted an anonymous MP (notably without saying which party they are from) as being set to resign from the organisation’s board, while The Times alleged that Chris Grayling supported Jenkin’s coup and the newspaper’s leader backed Cummings’ refusal to team up with Banks.

The dispute is, inevitably, a complex mixture of strategic differences (should the campaign be primarily about immigration, or based on a more optimistic presentation of an alternative outside the EU), personal differences (Cummings has history with various of the people involved), party differences (Leave.EU is essentially an outgrowth of UKIP) and disagreements about who should be the leading voices of the Leave campaign.

The current state of play appears to be as follows. Cummings has the backing of many, though possibly not all, of Vote Leave’s donors, the people who will fund the eventual referendum campaign. He has, however, made some mis-steps in managing relationships with various of the other political players in the anti-EU world. When Peter Bone and Tom Pursglove founded their Grassroots Out campaign – a grassroots ally of Banks’ Leave.EU – part of their reason for doing so was that they felt their proposals had been unfairly rebuffed by Cummings. Now, some of the other long-established eurosceptic MPs, particularly Jenkin and Cash, also feel MPs risk being sidelined in the Vote Leave operation.

Grayling’s position is more nuanced. His friends say that he wants a truce between Vote Leave and Leave.EU, and also that he wants an end to internal strife within Vote Leave. Contrary to The Times report, those friends deny he had his involvement in any attempt to oust Cummings. His position on this matters a lot – as I wrote earlier this month, unless any bigger Cabinet beasts opt to support the anti-EU cause, then he could well end up as the senior Conservative Leave figure.

While all of this goes on, other opportunities are being lost. The Prime Minister is in the deepest throes of his troubled renegotiation, and may be about to produce a rabbit of some sort – but instead of being pressed closely on the topic, he is in Brussels, quietly hammering out his plan. There remains a shortage of Labour figures supporting Leave, despite the all-time low levels of discipline in the Parliamentary Labour Party – the addition of compelling voices like Gisela Stuart should be a priority. And of course other Cabinet Ministers, mulling whether to come out for Brexit, are unlikely to be encouraged by the current state of the Leave campaigns.

What happens next could well decide whether Britain ends up in or out of the EU. The Vote Leave and Leave.EU teams met for lunch yesterday, in an atmosphere one person in the room described as “cathartic”. Their respective leaders, Matthew Elliott and Banks, are meeting this afternoon for further discussions about the relationship between the two groups. Banks says the sticking point is Cummings – though Elliott reportedly told the Vote Leave board this week that the two come as a package, and rather than ditch him they are minded to rein him in in some way.

It isn’t a happy picture. While Vote Leave isn’t perfect, though, it remains the best chance of the Leave side winning the referendum. Its team has the experience of fighting and winning referendums, and it is still possessed of the broader and deeper cross-party support. Despite Leave.EU’s claims, it has an active grassroots operation which has been hard at work in recent weeks. Some of its problems have arisen precisely because of Cummings’ and Elliott’s efforts to take the correct strategic decisions – all the research, including Leave.EU’s, suggests that immigration alone is not a sufficient argument to secure victory, for example. Relations with some parts of the eurosceptic movement have been fumbled, but Vote Leave is also correct to think that MPs cannot be the primary voice of the eventual campaign (an analysis on which they and Banks agree).

By contrast, while Leave.EU has certainly made up ground through its work with the Grassroots Out initiative (as I predicted a fortnight ago), it still has issues of its own. There are still concerns for many Conservative MPs that working with a campaign which is so close to the UKIP leadership would boost the appeal of the ‘People’s Army’, which makes it harder for many of them to consider supporting it. Even more important – and fundamental to the division between the two groups – is the issue of whether its strategy to win the referendum is the correct one. At a briefing last night, Gerry Gunster, their American consultant and veteran of thirty-odd referendums in the US, presented the top-line findings of his polling and focus group research. According to Gunster, the three strongest messages, in descending order, are controlling our borders, keeping our money at home and running our own country – but while border control is essential to rallying the anti-EU base, he found that saving money has the greatest appeal to the low income women who make up much of the crucial swing vote.

The question will therefore be whether there will come a point at which Leave.EU is willing to move on from rallying the base by banging the immigration drum and work to persuade those undecideds with other messages. The advice Banks is getting is good, but given that he told Channel 4 last night that he had put immigration “right at the centre of the campaign”, and attacked Vote Leave for not doing so, it looks doubtful that he is open to following it.

The Banks/Elliott meeting this afternoon will be important. But so will the work of a third man – Steve Baker, the Wycombe MP and Co-Chair of Conservatives for Britain. In a war-torn landscape, he’s effectively wearing the UN blue helmet, striving to keep Parliamentary eurosceptics united. He hasn’t spoken to other outlets on the matter at any length, but today he tells me this:

“I am concerned that we should be talking about what matters most to our constituents, in the pub, at home and in the supermarket – that is, all the issues that matter in their daily lives.

On Europe, I am deeply frustrated whenever we’re talking about anything other than putting the positive, optimistic case for leaving the EU. Anything else is a distraction from the main strategic goal of securing a vote to leave, which is the safer choice in the public interest.

As co-chair of Conservatives for Britain, I’ve been closely involved in the development and support of Vote Leave. The entire Vote Leave team has done a fantastic job of bringing us this far, this fast.

We must now take those steps necessary to ensure Vote Leave becomes the designated, cross-party campaign to leave the EU. Vote Leave can, and will, win.

It’s most unfortunate that distractions have played out in the press and I would ask all colleagues to refrain from press briefings on this issue of the first importance to our nation’s future.”

He could well play the decisive role in whether things get better or worse from here on.